Binocular telescope.



Patented Feb. 1, 19110.

NITEE sTATEs PATENT oEEIcE.

ALBERT KNIG, or JENA, GERMANY, AssiGNon To 'r1-1E FIRM or cAELzErss, or JENA; GERMANY.

BINOCULAR TELESCOPE.

Specification of Letters Patent.

'Patented Feb. 1, 1910.

Application iilet March 25, 1909. Serial No. 485,798.

To all whom it may concern.'

Be it known that I, ALBERT KNIG, a citizen of the German lEmpire, and residing at Carl-Zeiss strasse, J ena, in the Grand Duchy of SaXe-lVeimar, Germany, have vinvented a new and useful Binocular Telescope, of which the following is a specification.

The invention consists in an .improvement in binocular telescopes in which the two main casings are rigidly connected or formed in one piece and the distance bet-Ween the oculars can be adapted to the inter-pupillary distance without any optical parts other than the ocular lenses changing their position. In previously constructed binocular telescopes of this kind the means of altering the distance between the oculars consistedv in each ocular being shiftable in the direction toward the other in a groove on the common telescope casing, the ocular axis coinciding in a mean position with the axis of the image projected by the objective. In each position of the ocular the foot of the ocular formed as a slide surrounded the opening in the telescope casing corresponding to the ocular, so that this opening was always kept closed by the ocular.

According to the present invention, in binocular telescopes ofv the above kind, the alteration of the distance between the oculars can be eected by a means which is simpler and correspondingly cheaper and, above all,

rovides a closure for the ocular openings 1n the telescope casing, which is more proof, since no parts of its tight fitting surfaces ever remain exposed.

rI`he invention is based substantially on the consideration, that, from an o tical point of view, no reason exists for ui in the ocular axes particularly in the p ane o the image axes when shifting the oculars, since an equal displacement in height of both axes relatively to the image axes is as admissible as lateral displacements, which have alone hitherto been employed, because they alone fulfil the purpose of adapting the distance between the oculars to the inter-pupillary distance. The object of the invention is obtained by seating each ocular by means of a surface of revolution, which surrounds the ocular eccentrically, in or on a corresponding surface of the casing, which surface surrounds the ocular openin in the casing. Each ocular is thus rotatab e about the ams of its eccentric, whereby the distance belane between the axis of the ocular describes, in place of the former plane surface, a cylindrical one, which may be so situated, that it again contains the image axis, but besets it more conveniently. The rotatability of the ocular may be restricted to a part ofa rotation. In the event of the oculars being movable in ocular tubes for focusing the images, it is advantageous to have these tubes seated eccentrically on the telescope casing. Each ocular can be provided with a device to protect it against accidental displacement in any position desired or at least in each of several positions. It is an advantage to provide such a connection between the oculars, that in each distance between the oculare they lie symmetrically to the vertical median plane between the image axeswithout any special adjustment.

In the annexed drawing: Figure l is a diagram of the ocular system according to theinvention. Fig. 2 is a front view of la binocular telescope, the right ocular being removed. Fig. 3 is asectional plan View ol parts of the same telescope. Fig. 4 is a front view of another binocular telescope, the right oculartube being broken away. Fig. 5 is a sectional plan view of parts of the same telescope.

In Fig. l, the image axes and the diaphragms a of the field of view arranged concentric to them have the fixed distance b. The axes of the ecccntrics c have a somewhat greater fixed distance (l. The distance between the ocular axes may bc selected as desired between the Values c and f, the mean value of which is supposed to be equal to d, by rotating the oculars about the axes of the eccentrics, whereby the ocular axes describe cylindrical surfaces which appear in the ligure as circular arcs. As is evident from the figure, the image axes lie in this arrangementsomewhat lower than the ocullt) lar axes, when the distance ofthe latter is a mean one, and somewhat higher than the ocular axes when the distance between 'the latter has the maximum value f or the minimum e.

`Referring now to the first example, Figs. 2 and 3, the oculars g are slidable in ocular tubes h for the purpose of focusing the image. Eachocular tube possesses a foot flange h1 and is seated with the latters conical eccentric surface h2 in an annular part 1 of the telescope casing z', which is provided With a corresponding conical surface 2. In the front Wall of the casing z' there is an opening 3 arranged concentric to the image p axis and surrounded by the bearing surface 2, within which opening the image is formed, and the margin of which acts as the diaphragm of the lield of view. The rotation of the ocular tube/L is limited to about 120O by a slit h3 in the flange h1 of this tube and by a pin i* screwed into the casing z'. Each ocular tube l1, is provided With a worm wheel sector h4 concentric to the axis of theeccent'ric. The Worms 701 and k2, appertaining thereto, Wit-h right and left hand thread respectively, are fixed on the driving -axle which is journaled in a projection 5 of the casing z'.

In the second constructional example Figs. 4 and 5, it is supposed that partsl o the binocular telescope other than the oculars serve for focusing the image. oculars Z are therefore at once provided with a foot lange Z1, carrying the eccentric surface Z2. The annular parts m1 of the casing m are provided with the eccentric bearing surfaces m2 in the same manner as in the first example. The apertures m for the field of view in this case also lie concentric to the image axes and are surrounded by the bearing surfaces m2. Each ocular is r0- tatable individually, and is for a series of distancesbetween the oculars automatically secured against accidental displacement by the spring pawl m4 and a series of notches Z3.

I claim:

In a binocular a casing rigidly connecting both telescopes except the oculars and provided with two ocular openings and two surfaces of revolution, each of which latter surrounds one of the openings eccentrically, and two strai ht oculars, each with a surface of revo ution which surrounds the ocular eccentrically, the oculars being rotatably seated to the casing with their surfaces of revolution fitted to those of the casing.

ALBERT KNIG.

The 

